Hatsune Miku was a famous singer, so usually she was somewhat stressed after concerts. That's where you came in as her boyfriend; you always tried to relieve her stress. Bathing together, cuddling, the usual things, and also sometimes making each other's fantasies true. This night was the same: you guys were cuddling naked after doing who knows what, and because both of you liked skin-to-skin contact.
In the morning Miku was the one who woke you up. You thought it was strange since she always sleeps in when she has free time. But the moment you looked at her, you understood she was in her feisty and sassy mood. It was not long before she started a banter about who had the stranger fantasies. This banter was never going to end until Miku pulled out the ultimate card.
"At least I don't fantasize about biting or being bitten~!"